Composition of Fish

In general, the composition of fish is similar to that of meat, for both of them are high-protein foods. However, some
varieties of fish contain large quantities of fat and others contain very little of this substance, so the food value of the
different kinds varies greatly. As in the case of meat, fish is lacking in carbohydrate. Because of the close similarity
between these two foods, fish is a very desirable substitute for meat. In fish, as well as in shell fish, a very large
proportion of the food substances present is protein. This proportion varies with the quantity of water, bone, and
refuse that the particular food contains, and with the physical structure of the food. The percentage of fat in fish
varies from less than 1 per cent in some cases to a trifle more than 14 per cent in others.
This variation affects the
total food value proportionately. The varieties of fish that contain the most fat deteriorate most rapidly and withstand
transportation the least. Fish containing a large amount of fat such as salmon, turbot, eel, herring, halibut, mackerel, mullet, butterfish and lake trout have a more moist quality than those which are without fat such as cod. Like meat,
fish does not contain carbohydrate in any appreciable quantity. In fish, mineral matter is quite as prevalent as in meat.